A semi-multifunctional sialyltransferase from Bibersteinia trehalosi and its comparison to the Pasteurella multocida ST1 mutants.

Sialic acids are well known for their crucial roles in many physiological and pathological processes. Improvement in the efficacy of protein drugs, an increase in the anti-inflammatory activity of intravenous immunoglobulin, preparation of infant milk and the diagnosis of diseases are examples of why there is a need for efficient in vitro sialylation. Sialyltransferases are crucial enzymes for the synthesis of sialo-oligosaccharides.

Structural Features and Anti-coagulant Activity of the Sulphated Polysaccharide SPS-CF from a Green Alga Capsosiphon fulvescens.

Previously, we reported that the sulphated polysaccharides (SPS)-CF, a water-soluble polysaccharide isolated and purified from Korean green alga Maesaengi (Capsosiphon fulvescens, Chlorophyta), is a glucuronogalactomannan based mainly on the monosaccharide composition determined by high-performance liquid chromatography (HPLC) analysis after 1-phenyl-3-methyl-5-pyrazolone (PMP) labelling of sugars in the acid (trifluoroacetic acid (TFA)) hydrolyzates of SPS-CF, which showed mannose (55.4 mol %), galactose (25.3 mol %) and glucuronic acid (16.

Protein-RNA and protein-glycan recognitions in light of amino acid codes.

Background: RNA-binding proteins, in cooperation with non-coding RNAs, play important roles in post-transcriptional regulation. Non-coding micro-RNAs control information flow from the genome to the glycome by interacting with glycan-synthesis enzymes. Glycan-binding proteins read the cell surface and cytoplasmic glycome and transfer signals back to the nucleus.

Physical and bioengineering properties of polyvinyl alcohol lens-shaped particles versus spherical polyelectrolyte complex microcapsules as immobilisation matrices for a whole-cell Baeyer-Villiger monooxygenase.

Direct comparison of key physical and chemical-engineering properties of two representative matrices for multipurpose immobilisations was performed for the first time. Polyvinyl alcohol lens-shaped particles LentiKats® and polyelectrolyte complex microcapsules were characterised by advanced techniques with respect to the size distribution of the particles, their inner morphology as revealed by fluorescent probe staining, mechanical resistance, size-exclusion properties, determination of effective diffusion coefficient and environmental scanning electron microscope imaging. While spherical polyelectrolyte complex microcapsules composed of a rigid semipermeable membrane and a liquid core are almost uniform in shape and size (diameter of 0.

Degradation of polyphosphates by polyphosphate kinases from Ruegeria pomeroyi.

Polyphosphate kinases 2 (PPK2) are key enzymes for polyphosphate utilisation in bacteria. The genome of Ruegeria pomeroyi, a marine α-proteobacterium, includes three Pseudomonas aeruginosa PPK2 homologs. We expressed these homologs in Escherichia coli as soluble proteins, purified the protein products and compared their metal, pH and nucleotide preferences.

Protein-RNA recognition: cracking the code.

In early papers, the intent was to find a simple protein-RNA/DNA recognition code. Many people expected a one-to-one correspondence between amino acids and nucleic bases, similar to the code that specifies how one DNA base pairs with another. Despite the lack of such a code, which was evident in the first crystal structures, researchers were indeed unwilling to give up on the idea.

Synthetically prepared glycooligosaccharides mimicking Candida albicans cell wall glycan antigens--novel tools to study host-pathogen interactions.

The immunobiological efficacy of synthetically prepared mannooligosaccharides and a glucooligosaccharide mimicking the structure of Candida albicans cell wall glycans was assessed in vivo and in vitro to exploit immune responses. The exposure of mice splenocytes to BSA-based conjugates of synthetic oligomannosides and oligoglucoside revealed intense influence on T-cell subset polarization. The conjugates biased the immune responses towards Th1 and Th17 with respect to the prevalence of interferon-gamma (IFN-γ) and interleukin (IL)-17 (IL-17) over IL-4 and IL-10 levels.

Bacterial inclusion bodies as potential synthetic devices for pathogen recognition and a therapeutic substance release.

Background: Adhesins of pathogens recognise the glycans on the host cell and mediate adherence. They are also crucial for determining the tissue preferences of pathogens. Currently, glyco-nanomaterials provide potential tool for antimicrobial therapy.

Glycocodon theory--the first table of glycocodons.

Hydrophobic cellular membranes separate cells from an environment that is generally based on water. Therefore, it is not surprising that hydrophilic glycans and glycoproteins are exposed on the lipidic surface of membranes and that the glycocalyx has evolved in all basic cell types. During the evolution of multicellular life, the surface exposed protein-glycan interactions were taken as the origin of the language of cell-cell communication.

Polyphosphate--an ancient energy source and active metabolic regulator.

There are a several molecules on Earth that effectively store energy within their covalent bonds, and one of these energy-rich molecules is polyphosphate. In microbial cells, polyphosphate granules are synthesised for both energy and phosphate storage and are degraded to produce nucleotide triphosphate or phosphate. Energy released from these energetic carriers is used by the cell for production of all vital molecules such as amino acids, nucleobases, sugars and lipids.

Effect of the label of oligosaccharide acceptors on the kinetic parameters of nasturtium seed xyloglucan endotransglycosylase (XET).

Fluorescently labeled derivatives of a xyloglucan (XG) nonasaccharide Glc(4)Xyl(3)Gal(2) (XLLG) were used as glycosyl acceptors in assays of xyloglucan endotransglycosylase (XET) from germinated nasturtium (Tropaeolum majus) seeds. We have investigated how the type of the oligosaccharide label influences the kinetic parameters of the reaction. The fluorescent probes used to label XLLG were anthranilic acid (AA), 8-aminonaphtalene-1,3,6-trisulfonic acid (ANTS), fluorescein isothiocyanate (FITC), and sulforhodamine (SR), respectively.

The binding properties of the H5N1 influenza virus neuraminidase as inferred from molecular modeling.

The avian influenza H5N1 virus has emerged as an important pathogen, causing severe disease in humans and posing a pandemic threat. Substrate specificity is crucial for the virus to obtain the ability to spread from avian to human. Therefore, an investigation of the binding properties of ligands at the molecular level is important for understanding the catalytic mechanism of the avian influenza virus neuraminidase and for designing novel and specific inhibitors of H5N1 neuraminidase.

Dietary fibre degradation and fermentation by two xylanolytic bacteria Bacteroides xylanisolvens XB1A and Roseburia intestinalis XB6B4 from the human intestine.

Aims: To characterize fibre degradation, colonization and fermentation, and xylanase activity of two xylanolytic bacteria Bacteroides xylanisolvens XB1A(T) and Roseburia intestinalis XB6B4 from the human colon.

Methods And Results: The bacteria grew well on all the substrates chosen to represent dietary fibres: wheat and corn bran, pea, cabbage and leek fibres, and also on purified xylans. Roseburia intestinalis colonized the substrates more efficiently than Bact.

Polysaccharide microarrays for high-throughput screening of transglycosylase activities in plant extracts.

Polysaccharide transglycosylases catalyze disproportionation of polysaccharide molecules by cleaving glycosidic linkages in polysaccharide chains and transferring their cleaved portions to hydroxyl groups at the non-reducing ends of other polysaccharide or oligosaccharide molecules. In plant cell walls, transglycosylases have a potential to catalyze both cross-linking of polysaccharide molecules and grafting of newly arriving polysaccharide molecules into the cell wall structure during cell growth. Here we describe a polysaccharide microarray in form of a glycochip permitting simultaneous high-throughput monitoring of multiple transglycosylase activities in plant extracts.

Vibrio cholerae O1 Ogawa detoxified lipopolysaccharide structures as inducers of cytokines and oxidative species in macrophages.

Multidrug resistance in several strains of Vibrio cholerae has encouraged anti-cholera vaccine developmental attempts using various subcellular moieties. In order to examine the immunological efficacy of detoxified LPS (dLPS)-derived saccharide immunogens, ex vivo activation of mouse peritoneal macrophages (MPhis) was investigated. The immunomodulatory effect was evaluated via induction of the pro-inflammatory cytokines tumour necrosis factor-alpha, interleukin (IL)-1 alpha and IL-6 and acceleration of nitric oxide (NO) and reactive oxygen species (ROS).

Hybrid quantum mechanical/molecular mechanical investigation of the beta-1,4-galactosyltransferase-I mechanism.

The enzyme beta-1,4-galactosyltransferase-1 (beta4Gal-T1) catalyzes the transfer of a galactose residue from UDP-Gal to the C4-hydroxyl group of N-acetylglucosamine. The catalytic mechanism of beta4Gal-T1 was investigated using the hybrid quantum mechanical/molecular mechanical (QM/MM) method, with the QM portion containing 253 atoms treated with density functional theory (DFT) at the BP/DZP and BP/TZ2P levels. The remaining parts of the beta4Gal-T1 complex, 4527 atoms in all, were modeled using the AMBER molecular force field.

Conformational free energy surface of alpha-N-acetylneuraminic acid: an interplay between hydrogen bonding and solvation.

The conformational free energy surface of alpha-N-acetylneuraminic acid (Neu5Ac, sialic acid) in the space of ring-puckering coordinates was calculated using the metadynamics method. Free energy surfaces in vacuum and with an explicit solvent were calculated in GLYCAM 06 force field. In vacuum three structures are almost equivalently populated, namely, the (2)C(5) chair and the B(3,6)/(2)S(6) and (O)S(3) boat/skew-boat conformations.

NMR study of cellulose and wheat straw degradation by Ruminococcus albus 20.

Cellulose and wheat straw degradation by Ruminococcus albus was monitored using NMR spectroscopy. In situ solid-state (13)C-cross-polarization magic angle spinning NMR was used to monitor the modification of the composition and structure of cellulose and (13)C-enriched wheat straw during the growth of the bacterium on these substrates. In cellulose, amorphous regions were not preferentially degraded relative to crystalline areas by R.